"The problem is that it's nearly impossible to milk pigs. When sows are lactating, they get very aggressive. They're not docile like cows. They're smart, skittish, suspicious, and paranoid. They do not like you to get up in their business."

Lee managed to accumulate a few jars' worth of pigs' milk, from which he made half a cup of pig ricotta that he says was delicious. Getting even such a small amount of milk required jackal-like derring-do: Lee crept up on the sows while they were sleeping, frantically pinched at their tiny nipples, then ran away when they woke up and started to freak out.

Some people don't even know that a bunch of common cheeses come from sheep (not even goats).. so yeah why not pigs?
I sort of can buy that explanation a bit though, pigs being a lot bigger than chickens.

Many years ago, I used to live on a farm. And on that farm we had a pig. The pig's name was Rosie, and she was a 400-odd kilo Long White sow. She was generally very friendly, which was just as well. As well as using her as a baby pork making machine, we has her clean up the left-overs when we home-killed a cow for the freezer: the skull, shins, and guts would go into Rosie's paddock. She'd eat the head. Not like a dog would, eating the flesh off and sucking out the brain and leaving a bunch of crunched-up bone everywhere. She'd just make it disappear. Nothing left. Bone, horns, hooves, the lot.

The pig had been given to us by a neighbour who'd been letting her roam around paddocks. The neighbour had gotten sick of Rosie chasing, catching, and eating his free-range chickens.

400 kilos. Can chew up a cow skull. Agile enough to run and catch a fleeing chicken. You're damn right milking a pig doesn't sound like a great way to enhance your lifespan.